Patients with rheumatoid arthritis (RA) are at increased risk of serious infections, myocardial infarction (MI), and coronary heart disease (CHD), according to a study published in the Annals of the Rheumatic Diseases.

"Higher disease activity as measured by a panel of biomarkers was associated with higher rates of hospitalized infections, MI and CHD events. These findings add to the growing body of evidence that further strengthens the argument to strive for lower disease activity in RA," the authors wrote.

"This study used a commercially available multibiomarker disease activity test (MBDA), which measures disease activity through blood tests, to examine the relationship between disease activity and developing these comorbidities," said Dr. Eric L. Matteson, a professor of medicine at Mayo Clinic in Rochester.

"This test reflects that active disease is bad because it leads to not only joint damage and disability from the disease itself, but it increases the long-term risks of other problems such as heart attacks and infections," Matteson added.

"This study emphasizes the importance of disease control to reduce heart attacks and infections," advised Dr. Matteson, who was not involved in the study.

Dr. Paul Muntner, a professor of epidemiology at the University of Alabama at Birmingham, and colleagues conducted a longitudinal cohort study of older people living in the United States who had RA, were insured by Medicare, and had received MBDA testing as part of standard of care from a rheumatologist.

Using Medicare fee-for-service claims data for 2010 to 2014, the researchers examined hospitalization for pneumonia/sepsis serious infection events (SIEs), MI, and CHD. MBDA test scores, provided by Crescendo Biosciences (South San Francisco, California), ranged from 1 to 100 and were linked to the Medicare data.

Data from 17,433 and 16,796 patients eligible for the SIE and MI/CHD analyses, respectively, were analyzed. The patients’ mean age was 69, 79% were women, 81% were white, and 38% were disabled.

The cohort’s most commonly used medications were methotrexate (54%) and oral glucocorticoids (53%). Patients with lower MBDA scores tended to be younger, have lower comorbidity burden, and use fewer glucocorticoids – but more biologics. In all, 452 SIE events, 132 MIs, and 181 CHD events occurred during 16,424 person-years of follow-up.

Higher MBDA scores were significantly associated with SIEs (adjusted hazard ratio, 1.32, per 10-unit MBDA score change). Higher RA disease activity, by MBDA score, was linked with higher adjusted HRs for MI (1.52) and CHD (1.54). Analyses excluding C-reactive protein from MBDA were consistent with the overall results.

"This is some of the best data available to suggest a link between RA and heart disease," Dr. Graf, director of the Rheumatoid Arthritis Clinic at Zuckerberg San Francisco General Hospital and Trauma Center. "I think these results prove the hypotheses that inflammation drives cardiac disease."

"These results suggest that we should be treating patients as aggressively as we can," he advised. "Maybe instead of treating a patient by gestalt, we need to measure the total disease activity present and treat that person to a target."